Continuous-heating furnace



Naw. 18, 1924. 1,515.85l

J. F. Fl-:RM

CONTINUOUS HEATING FURNACE Filed May 2', 1923 f 3 Sheets-Sheet 2 r ma@ W .W A e v0 #2% x www u :l l

J. F. FERM CONTINUOUS HEATING FURNACE Filed May 2, 1923 s sheets-sheet 5 F I E 8 t u or rrr'rsrunen, PENNSYLVANIA.

coNrINUoUs-rnve runNacn application mea Nays, leas. aerial No. e'eaott.

i To all whom. `t 'may concern.:

Be it known that I, JOHN F. FERM, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and the State of Pennsylvania,'have made a new and useful Inventionv in Continuous- Heating Furnace, of which the following is a specification.

My lnvention relates to a continuous heat- 1n slas'or billets prior to rolling or forglng. An object of my invention 1s to construct a multiplehearth furnace having any desired capacit and which occupies no more door space than is necessary for a single hearth furnace of the old type. Another object is to provide a multiple hearth furnace of any desired capacity which will require less labor than the number of furnaces of the old type required for a lightA capacity and to decrease the fuel" necessary by decreasing the radiating surface and at the same time decreasing the first cost of installation.

These and other objects l attain bymy invention, one embodiment of which is illustrated in the accompanying drawings `1nv which Figure 1 is a verticallongitudinal section through the center of the. furnace. Fig. 2 is a horizontal section along the line 2-2 of Fig. 1 looking in the direction of the arrows. Fig. 3 is a horizontal section on a line 3-3 of Fig. 1 looking in the di` rection of the arrows.- Fi 4 is a vertical showin the slots in the furnace wall f 'throug which the transfer mechanismf extends and the means for sealing thcseslots.

Fig. 8 is an enlarged section on the line 8 8 of Fig. 1 showing the transfer arms in their .lowest-position.

The furnace illustrated com rises a `bottom hearth 1 and upper heart vcomposed of water cooled skids2 and 3. At thebottom of the furnace is provided a nishing hearthfl for removing theblack'spots on slabs or billets which are caused by contact with the water cooled skids which form the upper preheating hearths. The bottom of the finishing hearth 4 has non-water cooled skids, or if desired may be covered with magneslte'to prevent excessive wear. The

furnace forl preheating ingots, blooms,

'roof of the main furnace chamber.

ward a dat portion 5 which` is opposite the' discharge door. 6.

The skids, 2 and 3 which form the upper hearths are supported on water cooled supports 7 which may be covered with a refractory insulation to prevent heat loss if desired. Charging doors 8 are provided at one end of the furnace for charging the ,preheating hearths. Outside each set of charging doors 8, I provide 9, 10 and 11 for supporting thel cold stock preparatory to its bemg'placed in the furnace. A triple ram pusher 12 is provided for pushing the cold stock into the furnace.

Two or more chargn vided for each hearth. ach changing ram is independently operable so that if there is is more than vone row of'material on a preheating hearth each row can be independently advand. I

At the end of the furnace opposite the charging doors are the air ports 13 for directing the air blast into the combustion rams 12' are prochamber for the main furnace. These air ports 13 are connected with an air header M'for preheated air which is drawn from va preheating 'chamber 15 by a fan or blower 15. rllhe air is preheated in this chamber by radiation from the hottest part of the preheating chamber 15 connects with a similar chamber 16, constructed in the furnace between the lowest vpreheati'ng hearth 1 and the nishing hearth 4, by up-takes 17 on the sides of the main furnace. Fuel gas forr the combustion chamber 18 of the main fur-a nace is admitted through a fuel flue 19 and fuelportsao. v

The air blast is admitted to the finishing hearth 'through 'air pipes 21, which are con- I nected to an air header 22 which i'n turn is connected to a header 23 for the preheated air. The air for the nishing hearth is preheated in a' coil 24 located in the flue 25 of slots extend water cooled arms 31 for trans-- ferringf material from 4the preheatingl The..

.lot

hearths to the lower finishing hearth 4.

u These transferrin arms 3l are pivoted to a shaft 32 outside t e furnace wall and have geared segments 33 fastened to them. Pinions 34 are secured to a motor driven shaft 35 and mesh withi the geared segments for oscillating the arms. Pushers 36,'

whichv may be either hydraulic or motor driven, areprovided for pushing the preheated material from the arms onto the finishing hearth 4, when the transfer arms are ,in their lowest position and at the same time moving the preceding slabs or billets, which are already on the finishing hearth 4, toward the discharge door 6.

Segment slides 37 are secured to the trans- 'fer arms 31 and form air seals for the slots 30 in the'arcuate wall 29 of the furnace through which the arms 31 extend. These slides 37 extend above and below the arms 31 so as to seal the slots in any position of the arms.

The usual inspection doors 38 are provided for observing the condition of the mate rial within the furnace.

Assuming that the three lpreheating hearths and the finishing hearth are covered with one or two solid rows of billets, slabs or the like, depending upon the length of the stock being heated, as soon as'heated stock is discharged from the furnace through the.

discharging door 6, by means of an ordinary pinchroller pusher, in the usual manner the operator inspects the upper preheating hearths through the peep holes or inspection doors 38 and rotates the motor driven arms 31 up opposite the hearth with the hottest material. The ram Ifor the corresponding hearth on the furnace charger 12 is then pushed forward thereby charging cold stock into the furnace on that hearth and at Vthe same time pushing hot stock from the other end of that hearth on to the transfer arms 31. By rotating the pinions 34 which are in meshwith the segments 33 on the transfer arms 3l these arms are lowered with the pre- .heated material' to the bottom or finishing hearth 4. At this `point the pushers 36 shove onebillet at a time off the arms onto the finishingv hearth thereby advancing one I row of material along the finishing hearth.

coldair from entering the furnace.

however, does not prevent the pushers* 31 from delivering stock at'a given place for discharging through'the door- 6.

The stock will be heated to practically rolling or forging temperature on the preheating hearths, except for black spots, or unheated spots, which are due to contact with the water cooled skids 1, 2 and 3 which ,form the preheating hearths. The finishing hearth -is provided to remove these black spots by having the billets slide on plane nonwater cooled skids set in an ordinary fire brick hearth or on magnesite for final heat- 1n iglhe heat for the main hearths is furnished by the products of combustion from the finishing hearth, which should be at a high temperature, and also a second firing arrangement as has been herein above described. y The proportion of heat furnished by each source is dependent on the tonnage of hotproduct required and the variation should be made in fuel used at the upper firing chamber 18 in order to maintain-a constant temperature. on the hearth by a practically non-variable fue consumption in the lower firing chamber for producing a uniformly heated product. The

products of combustion from both sources sweep along on all sides of the billets on the skids 1, 2 and 3. In this way any uneven temperature of one hearth is regulated by radiation to the next hearth, thus tending to maintain an even temperature at various distances from the sources of heat. This reresults from having the upper preheating hearths made only of skids so as to expose all sides of the material to be heated. At the chargin end the products of combustion passed own around the ends of the stock at the widened. section of the' furnace to the fiue-and then to the stack.

I have illustrated a furnace equipped for gas firing but it is obvious that my invention igsu equally suit-able for furnaces using other els.

Having thus described one embodiment of my invention what I claim is 1. A-oontinuous heating furnace having a plurality of super-imposed hearths, a chargfinishin l lng opening for each hearth and a common discharge opening.

2. A continuous heating furnace having a plurality of super-imposed preheating hearths and a finishing hea'rth for finishing material received from said preheating hearths.

A 3. A continuous heating furnace having a plurality of super-imposed preheating hearths and a finishing hearth communicating with said preheating hearths.

4. A. continuous heating furnace having aplurality of .preheating hearths, a combus- `tion` chamber therefor; a finishing hearth, .an independent combustion chamber for the a plurality pf superimposed 'preheating iiaeei hearths, a finishing hearth lfor receiving material from said preheating hearths, charging openings for each preheating hearth, and a discharge opening for said finishing hearth.

6. A continuous heating furnace having a plurality of preheating hearths, a downwardly inclined nishing hearth having a flat portion, for receiving material from said preheatin hearths, charging openings for each pre eating hearth and a discharge openingV for said finishing hearth opposite said flat portion.

7.' A continuous heating furnace having a pluralit of preheating hearths, a finishing hearth or receiving material from said reheating hearths, a plurality of indepen ent sets ofcombustion ports, a common flue forl I plurality of preheating heartlis, means for feeding material along said preheating hearth, a finishing hearth, and means for conveying material from any desired 'preheating hearth to said finishing hearth.

10. A continuous heating furnace having a plurality of super-imposed preheating hearths, a finishing hearth and means for transferring material from any desired prel heatin hearth to said finishing lriearth.l

11. continuous heating furnace having a plurality of preheating hearths, a finishing hearth for receiving material from said preheating heartlis, means for transferring i a plurality of super-imrwm preheating heartlis, pivoted-arms forl transmaterial from any desired preheating hearth to said finishing hearth and means for am .ing material onto said finishing hearth from said transfer means.

12. A continuous heating furnace having preheating hearths, a finishing hearth beneath said preheating hearths and means for transferring material' from any desired preheating hearth to said finishing hearth.

13. .A continuous heating furnace having a plurality of preheating hearths, a finishing liearthffor receiving material 'from said ferring material from any desired preheating hearth to said finishing hearth and means for feeding material from"saidjtrans fer arms to said finishinr hearth.

14. A continuous heating furnace having a ,pluralityl ofsuper-imposed preheating liearths, a finishing vhearth beneath said preheating hearths .and vmeansfor transferring material from any ldesired preheating hearth preheating hearth to said to said finishing hearth comprising pivoted arms and means for oscillating said arms.

15. A continuous heating furnace having a plurality of preheating hearths, air supply means therefor including an air preheating l,means embracing said preheating hearths, a

finishing hearth and means for supplying preheated air thereto.

16. A continuous heating furnace having a plurality of super-imposed preheating hearths, air supply means therefor including an air preheating means for rsaid preheating hearths, a finishing hearth and l means for supplying preheated air thereto.

17. A continuous heating furnace having a plurality of super-imposed preheating hearths, air supply ing an air preheating means embracing said preheating heartlis, a finishing hearth beneath said preheating hearths and means for supplying preheated air thereto.

18. A continuous heating furnace having a plurality of preheating hearths, a finishing hearth, pivoted arms for transferring material from any desired preheating hearth to said finishing hearth, a geared segment secured to said arms and a pinion in mesh with said segment for oscillating said arms.

19. A continnu'sf' heating furnace havingA a plurality of super-imposed preheating hearths, a finishing hearth, horizontally pivoted arms for transferring material from any desired preheating hearth to the finishing hearth, geared segments secured to said arms and pinions y,meshing with said segments for oscillating said arms.

20. A continuous heating furnace having a plurality of preheating hearths, a finishing hearth, transfer arms horizontally pivoted outside the furnace and extending inwardly through slots in the furnace wall for transferring material from any desired preheating hearth 4to the finishing hearth, means on said arms for sealing said slots and means for oscillating said arms.

21. .A continuous heating'furnace having a7plurality of super-imposed preheating heartlis, a finishing hearth beneath said preheatinv hearths, transfer arms horizontally pivote outside the furnace and extending inwardly through slots in the furnace Wall for transferring material from any desired preheating hearth to the finishing hearth,

lmeans on saidarms for sealing said slots .to the finishing hearth, slides on said arms for sealing said-slots, geared `segments secured-to said arms and pinions meshing with said segments for oscillating said arms.

means therefor includ- 23. A continuous heating furnace having a plurality of super-imposed preheating hearths, a finishing hearth, transfer arms horizontally pivoted Outside the furnace and extending inwardly through slots in the furnace wall for transferring material from any desired preheating hearth to the finish ing hearth,`slides on said arms for sealing said openings, geared segments secured to said arms `and pinions meshing with said pushers for feeding the preheated material on to said finishing hearth.

25. A continuous heating furnace having a plurality of super-imposed vpreheating hearths, a finishing hearth, transfer arms horizontally pivoted outside the furnace and extending inwardly through slots in the furnace wall for transferring material from any desired preheating hearth to the finish' ing hearth, slides on said arms for sealing said openings, geared segments secured to said arms, pinions meshing with said segments for oscillating said arms and pushers for feeding the preheated material on to said finishing hearth. 1

26. A continuous heating furnace h aving a plurality of preheating hearths, a finlshlng hearth, for finishing material received from the preheating hearths, fuel ports and air inlet ports for said preheating hearths, 1ndependent fuel ports and air inlet ports for said finishing hearth, and a commom flue for the products of combustion.

27. A continuous heating furnace having a plurality of super-imposed preheating hearths, a finishin hearth beneathvsaid prevheating hearths or finishing material rethe products of combustion.

linlet ports for said finishing hearth, air

preheating means for eachA set ofair inlet ports and a common flue for the products of combustion;y

2.9. A continuous heating furnace having a pluralit of preheating hearths, a finish'- ing heart for finishing material received from the preheating hearths, fuel ports and air inlet ports for said preheating hearths, an air preheating means embracing said preheating hearths and connected'ito said air inlet ports, fuel ports and air inlet ports for said finishing hearth and air preheating means for said second air inlet ports.

30. A continuous heating furnace having a plurality of super-imposed preheatin hearths, a finishing hearth beneath sai preheating hearths for finishing material received from the preheating hearths, fuel ports and air inlet ports for said preheating hearths, and air preheating means embracing said preheating hearths and connected to said air inlet ports, fuel ports and air inlet ports for said finishing hearth and air preltieating means for said second air inlet nor S- 31. A continuous heatin furnace having a plurality of preheating earths, a finishing hearth for finishin material received from said preheating hearths, fuel ports and air inlet ports for said preheating hearths, fuel ports and air inlet portsofor said finishing hearth, air preheatin means for each set of air inlet ports, c arging openings for each' preheating hearth, a discharge opening for said finishing hearth and means for transferring material from said preheating hearths to said finishing hearth.

32. A continuous heating furnace having a plurality of super-imposed preheatin hearths, a finishing hearth, beneath sai preheating hearths for finishing material received from said preheating hearths, fuel ports and air inlet ports for said preheating hearths, fuel plorts and air inlet ports for said finishing earth, air preheatin means for each set of air inlet ports, c arging openings for each preheating hearth, a discharge opening for said finishing hearth, and means for transferringmaterial from said preheating hearths to said finishing hearth.

'33. A continuous heating furnace havin a' plurality of preheating hearths com ose of water cooled skids, a nishin heart /and means for conveying materia? from said preheating hearths to said finishing hearth.

34;. A continuous heating furnace having a plurality of Asuper-imposed reheating hearths, composed ofwater cooled) uncooled finishing hearth and water cooled means for transferring material from said preheating hearths on to said finishing hearth.l y l 35. A continuous heating furnace having a plurality of super-imposed reheating hearths composed of water cooled) skids', an uncooled finishing hearth beneath said preheating hearths,vand water cooled means for skids, an

amasar' hearths to said finishing hearth.

36.- A continuous heating furnace havin a plurality of preheating hearths compose of vwater cooledl skids, an uncooled nishing hearth, water cooled arms pivoted outside the furnace and extending through slots inv the furnace wall, slides on said arms for sealing said slots, geared segments on said arms, pinions meshing with' said geared segments for oscillating said arms and means for pushingmaterial received fromf said pre-r heatin hearths ofi' the arms on to said finishing earth.

/37. A continuous heating furnacev having Ja plurality of preheating hearths, a finishing hearth and pivoted transfer mechanism for conveying material from any desired preheating hearth to said finishing hearth and means for operating said mechanism.

38. A continuous heating furnace having a plurality of preheating hearths, a finishing hearth, pivotedv transfer mechanism for transferring material from any desired preheating` hearth to saidinishing hearth and means for feeding material onto said finishing hearth from said transfer mechanism.

39. A continuous heating furnace having a plurality o'f super-.imposed preheating hearths, a finishing hearth beneath said preheating hearths horizontall pivoted transfer mechanism. for trans erring material from any desired preheating hearth "to-said inishing hearth vand means for feeding material onto said finishing hearth from said transfer mechanism.

40. A continuous heating furnace having said mechanism.

a plurality of super-imposed preheating hearths, a finishing hearth beneath said preheating hearth, horizontall pivoted transfer mechanism for' trans erring material from any desired preheating hearth to said nishing hearth and means for operating 41. A continuous heating furnace having a plurality of preheating-hearths, a lower finishing hearth and means for lowering material from any preheating hearth to said finishing' hearth.

42. A continuous heating furnacehaving a plurality of super-imposed preheating hearths, a lower finishing hearth beneath said preheating hearths and means for lowering material from any preheating hearth to said finishing hearth.

43. A continuous heating furnace having a plurality of. preheating hearths, a lower finishing' hearth, means for lowering material from any preheating hearth to said finishing hearth and means for .feeding .ma-

terial'onto'said finishing hearth from said lowering means. 44. A continuous heating furnace having a plurality of super-imposed preheating hearths, a lower finishing hearth beneath said preheating he-arths, means for lowering material from any desired preheatinghearth to said finishing hearth and means for feeding material onto' said preheating hearth from said lowering means.

In vtestimony whereof", I have hereunto f subscribed my name this 26th day of April,

JOHN F. FERM. 

